1. Department of Radiology, University of Wisconsin-Madison, Madison, WI 53792.
2. Mirus Bio Corporation, Madison, WI 53719.
3. Departments of Pediatrics and Medical Genetics, Waisman Center, University of Wisconsin-Madison, Madison, WI 53706.
4. Department of Biostatistics, University of Wisconsin-Madison, Madison, WI 53792.
5. Transgene S.A., Strasbourg 67082, France.
6. Present address: Association Française contre les Myopathies (AFM), 91002 Evry Cedex, France.